Air cleaner assembly

ABSTRACT

In at least some embodiments, the present invention relates to an air cleaner having a housing portion, and a low profile rain cover having an opening on an underside of the cover to allow unfiltered air to enter into the air cleaner. Also, in at least some embodiments, the present invention relates to an air cleaner including a housing and an additional component by which the air cleaner is capable of being directly coupled to a carburetor inlet. In some such embodiments, one or more protrusions can be provided within a channel formed by the housing/additional component to influence air flow. Further, in at least some embodiments, the present invention relates to an air cleaner having a shaped wall formed on a housing portion, where the shaped wall includes both an interior surface and an exterior surface by which air flowing within the air cleaner is imparted with helical motion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. nonprovisional patentapplication Ser. No. 11/548,912, entitled “Air cleaner Assembly” filedon Oct. 12, 2006, which also claims the benefit of U.S. provisionalpatent application No. 60/726,309 entitled “Air Cleaner Assembly” filedon Oct. 12, 2005, each of which is hereby incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates to filtration systems and methods, forexample, air filtration systems and methods such as those employed inconjunction with internal combustion engines.

BACKGROUND OF THE INVENTION

An air cleaner is a device installed on an internal combustion engine toprovide clean air for combustion within the engine cylinder. Heavy dutyair cleaners are typically used on engines that power devices used forindustrial purposes, for example construction equipment or agriculturalequipment.

FIG. 1 (Prior Art) provides a perspective, partially-exploded view of atypical conventional heavy duty air cleaner assembly 0. As shown in FIG.1, the air cleaner assembly 0 includes an air cleaner 3 having a tubularshaped housing 4 and a filter element 8 that uses pleated paper tofilter dust and other debris out of the combustion air flow. The filterelement 8 is placed inside the tubular shaped housing 4, and is designedto provide a large filter paper surface area to increase the time theengine can be operated before cleaning or replacing the filter element.A removable end cap 5 can be affixed to and removed from the housing 4to provide access to the filter element 8, allowing replacement orservicing of the filter element. The end cap 5 in the present view isshown to be attached to the housing 4 even though the filter element 8is shown disassembled from (and outside of) the housing.

In addition to the housing 4, end cap 5, and filter element 8, FIG. 1shows the air cleaner 3 to include a number of other components. Inparticular, the air cleaner 3 includes a mushroom-shaped rain cap 1 thatis configured to be positioned onto (and over) an upwardly-extendinginput port 28 of the housing 4. Also, the air cleaner includes coverretaining clips 6 by which the end cap 5 is fastened to the housing 4, adirt ejection valve 7, and a secondary or redundant filter element 9(sometimes referred to as a “safety” filter element) that fitsconcentrically within an inner cylindrical space within the filterelement 8 when the filter elements are installed within the housing. Itshould be noted that FIG. 1 shows the filter elements 8, 9 to be inpositions that are approximately 180 degrees different from those thefilter elements would occupy when implemented within the housing 4 andend cap 5 as shown, in order to show open ends of those filter elementsthat only exist at one of the two axial ends of each respective filterelement.

The air cleaner assembly 0 further includes, in addition to thecomponents of the air cleaner 3, an air duct 11, an adapter (air duct tocarburetor) 13, gaskets 14 and 17, hose clamps 10, air cleaner brackets18 and 24, and an air cleaner body clamp 20. Typically, the filtered airoutput at an output port 29 of the air cleaner 3 is ducted to acarburetor or throttle body on a spark ignited engine, or to an intakemanifold on compression ignition engines. In the present embodiment, theair cleaner assembly 0 is shown to include the intake manifold 15. Also,the air cleaner assembly 0 includes various fastening components 2, 12,16, 19, 21, 22, 23, and 25, which can include, for example, bolts,washers, screws, etc. The air cleaner 3 is mounted upon the engine byway of certain of these fastening components, along with the air cleanerbrackets 18, 24 and the body clamp 20, which is coupled to the aircleaner brackets and surrounds the tubular housing 4. Also, thefastening component 2 is used to clamp the rain cap 1 to the input port28.

To further extend the service life of the filter element 8, the tubularhousing 4 of the air cleaner 3 is designed to spin the incoming airwithin the air cleaner, particularly within an annular space existingbetween the outer wall of the housing (and end cap 5) and the filterelement 8 positioned within the housing. Dirt particles suspended in theincoming air centrifuge out against the outer walls of the tubularhousing 4, eventually reaching the dirt ejection valve 7, which allowsfor the dirt to exit the air cleaner 3. Thus, the amount of dirt anddust that reaches the filter element 8 is significantly reduced.Further, the rain cap 1 is installed onto the input port 28 of thehousing 4 to prevent ingestion of moisture and to prevent other largedebris from entering the housing.

While relatively heavy dirt particles tend to exit the air cleaner 3 byway of the dirt ejection valve 7, the otherwise unfiltered air continuesthrough the air cleaner 3 by passing radially inward through the tubularpleated paper of the filter element 8, and then proceeds furtherradially inward through the secondary filter element 9 as well, untilthe air reaches a central axial tubular passage within the secondaryfilter element. The filtered air then passes through and out of theaxial tubular passage by way of the output port 29 of the tubularhousing 4. The filtered air exiting the output port 29 of the tubularhousing 4 then is ducted to the engine.

As mentioned, FIG. 1 shows the air cleaner 3 employed as a heavy dutyair cleaner in connection with the intake manifold 15. When the aircleaner assembly 0 is assembled and installed in relation to an engine(not shown), the air duct 11 is coupled between the output port 29 ofthe air cleaner 3 and the adapter 13 by way of the hose clamps 10 (andrelated fastening components), where the adapter 13 in turn is coupledto the intake manifold 15 with one of the gaskets 14 positionedtherebetween. The air duct 11, which can be a rubber hose, thus conductsthe filtered air into the engine intake manifold 15 by way of theadapter 13. The hose clamps 10 are used to provide air tight sealsbetween the air duct 11 and each of the output port 29 of the aircleaner housing 4 and the adapter 13 (or, in cases where the adapter isnot used, to the intake manifold itself).

Although conventional air cleaners such as that of FIG. 1 successfullyfilter air, it would be desirable if certain aspects of such aircleaners could be improved. For example, with respect to the rain cap 1as can be used on such air cleaners, the rain cap is not ideal insofaras it constitutes an additional, large component that protrudes off ofthe housing. Not only is the protruding rain cap vulnerable to beingknocked off of the air cleaner assembly, but also it increases theoverall size of the air cleaner assembly 0 in a manner that makes itmore cumbersome to install and use. This can particularly limit theapplicability of the air cleaner 3/air cleaner assembly 0 in somecircumstances where a smaller device is required.

Further for example, while conventional air cleaners such as the aircleaner 3 are designed to achieve a swirling, helical motion of theunfiltered air as it enters into the air cleaner housing, such aircleaners typically only have a chamber that, due to the shape ofinterior wall, positively influences the air to take this path over thecourse of about 90 degrees. Because of the limited degree to which theair is influenced to take on the swirling motion, the swirling motionimparted to the unfiltered air is often not as strong as might bedesirable in order to achieve maximal centrifugal force action upon dirtparticles and other large debris such that such particles and debris aredirected away from the filter element within the air cleaner.

Additionally, the manner in which the air cleaner 3 is coupled to theintake manifold 15 and/or other portions of the engine on which the aircleaner is mounted requires a large number of components (e.g., the airduct 11, the hose clamps 10, the adapter 13, the body clamp 20, numerousassorted fastening devices, etc.). Consequently, assembly of the aircleaner 3 onto an engine can be a relatively complicated operation. Forexample, it can be relatively difficult or time-consuming to assemblethe air duct 11 in conjunction with the housing 4 and the adapter/intakemanifold 13, 15 in a sealed, airtight manner. Further, because of thelarge number of parts, the costs associated with not only the assemblyof the air cleaner 3 onto an engine but also the manufacturing of thecomponents of the air cleaner assembly 0 are higher than what they mightdesirably be.

Therefore, it would be advantageous if an improved design for an aircleaner assembly could be achieved. In particular, in at least someembodiments, it would be advantageous if a cumbersome mushroom-shapedrain cap atop a protruding, upwardly-extending air cleaner input portwas not necessary, and/or if the air cleaner assembly was a package ofsmaller size or more practical shape so as to allow the air cleanerassembly to be implemented in smaller spaces or in certain applicationsrequiring such smaller packages or packages of a less cumbersome size orshape. Also, in at least some embodiments, it would be advantageous ifthe swirling action within the air cleaner could be enhanced. Further,in at least some embodiments, it would be advantageous if the number andcomplexity of parts used in assembling the air cleaner to anengine/intake manifold could be reduced.

BRIEF SUMMARY OF THE INVENTION

In at least some embodiments, the present invention relates to an aircleaner that includes a housing portion having an inlet, a filterelement positioned within the housing portion, and a rain cover coupledto the housing portion so that the inlet opens into the rain cover. Therain cover includes an opening along an underside of the rain cover toallow air to enter into the air cleaner, and at least a preponderance ofthe rain cover extends substantially no higher than the housing portion.

In at least some further embodiments, the present invention relates toan air cleaner that includes a filter element, and a housing withinwhich is positioned the filter element and further having an inlet andan outlet, the outlet being formed by way of an integrated extension.The integrated extension is configured to allow the housing to bedirectly coupled to at least one of a carburetor and an intake manifoldwithout any intermediate air duct.

In at least some additional embodiments, the present invention relatesto an air cleaner that includes a filter element configured to filterair, and a housing portion within which is positioned the filterelement. The housing portion includes a shaped wall, where the shapedwall includes an exterior surface and an interior surface, and where theshaped wall influences a path of the air that is to be filtered both asthe air passes alongside the exterior surface and as the air passesalongside the interior surface.

Also, in at least some embodiments, the present invention relates to amethod of operating an air cleaner. The method includes receiving air ata downwardly-opening orifice formed within a rain cover, imparting ahelical motion upon the air as it proceeds within a first chamber formedbetween the rain cover and a housing portion and providing the air intoan inlet of the housing portion. The method additionally includesfurther imparting the helical motion upon the air as it proceeds withina second chamber of the housing portion, filtering the air, andoutputting the filtered air.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective, exploded view of a Prior Art air cleanerassembly;

FIG. 2 is a perspective view of an improved air cleaner in accordancewith at least one embodiment of the present invention;

FIG. 3 a is a perspective, partially-exploded view of the improved aircleaner of FIG. 2 in which an end cap and a half-duct air channel inparticular are exploded from the air cleaner;

FIG. 3 b shows a top view of a housing portion of the improved aircleaner of FIG. 2;

FIGS. 3 c and 3 d show cross-sectional views of the housing portion ofFIG. 3 b taken along lines C-C and D-D of FIG. 3 b, respectively;

FIG. 4 a is a perspective view of a rain cover of the improved aircleaner of FIG. 2;

FIG. 4 b is a perspective view of the housing portion of FIG. 3 b,combined with an end cap, of the improved air cleaner of FIG. 2;

FIGS. 5 and 6 show cross-sectional views of the housing portion of FIG.3 b taken along lines 5-5 and 6-6 of FIG. 3 b, respectively;

FIG. 7 shows a perspective, exploded view of the improved air cleaner ofFIG. 2 along with additional engine components;

FIG. 8 shows a perspective, bottom view of an alternate embodiment of ahousing portion similar to that of FIGS. 3 a-3 d except insofar asadditional fins are formed within and extend from a channel along thebottom of the housing portion;

FIG. 9 shows a perspective, top view of an alternate embodiment of anadditional housing component that can be employed in conjunction withthe housing portion of FIG. 8; and

FIG. 10 shows a cross-sectional view of the housing portion of FIG. 8when assembled to the additional housing component of FIG. 9, takenalong a line 10-10 of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 2, an improved air cleaner 100 in accordance withcertain embodiments of the present invention is shown in perspectiveview. In addition to having a main tubular or cylindrical housingportion 104 and an end cap 105, the improved air cleaner 100 alsoemploys certain additional structures discussed in more detail withrespect to FIGS. 3 a-d. One of these additional structures is anadditional housing component 107 that assists in conveying filtered airoutput by the air cleaner 100 to a carburetor, intake manifold orsimilar engine component (see FIG. 7), in place of the air duct 11,output port 29 connected to the air duct, clamps 10 and adapter 13 ofconventional embodiments such as that shown in FIG. 1. The housingportion 104 and additional housing component 107 alternatively can bereferred to as a first (or upper) housing or base, and a second (orlower) housing or base, respectively.

Further as shown in FIG. 2, in place of the body clamp 20 (and relatedcomponents) of FIG. 1, the air cleaner 100 includes integral mountingbrackets 138 that allow for the air cleaner 100 to be directly mountedonto an engine (or other surface). Additionally as shown, the improvedair cleaner 100 employs a rain hood or cover 128 as shown in more detailin FIGS. 4 a and 7 rather than the rain cap and associatedupwardly-directed input port of the air cleaner 3 of FIG. 1. When theair cleaner 100 is fully assembled, both the end cap 105 and the raincover 128 are coupled to the housing portion 104 by way of retainingclips or attachment clasps 103, which typically are metal, plastic orrubber.

The present air cleaner 100 is intended to be used as a heavy duty aircleaner, for example, for use in conjunction with a 30 to 40 horsepowerv-twin engine. However, the present invention is also intended toencompass a wide variety of other embodiments of air cleaners ofdifferent sizes, shapes and composition (not necessarily heavy duty)other than the air cleaner 100, including air cleaners that areapplicable with respect to other types of engines as well as withrespect to other devices that require air filtration. Indeed, it is alsoenvisioned that embodiments of the present invention will be employed incircumstances requiring the filtration of substances other than airincluding, for example, other gases, water, or oil. Among thesecircumstances are ones in which annular/cylindrical filtering media areemployed and where swirling of the substances is advantageous as apreliminary filtration step prior to passage of the substances throughthe filtering media.

Turning to FIG. 3 a, the improved air cleaner 100 is shown in aperspective, partially-exploded view, in particular, with the end cap105 exploded from the cylindrical housing portion 104 so as to reveal aprimary filter element 108 positioned within and extending out from thehousing portion. Further, the additional housing component 107 is shownexploded from the cylindrical housing portion 104. The additionalhousing component 107 has an elbow (or curved integral adapter) 125 anda half-duct channel 126, formed as one piece. The half-duct channel 126forms a trough (see also FIG. 5) that at one end has an outlet that isthe elbow 125. The housing portion 104 is shown to include acomplementary half-duct or mating channel 127 along a bottom surface 119of the housing portion. An outlet channel 117 connects the interior ofthe air cleaner 100 with the mating channel 127.

When the air cleaner 100 is assembled, the additional housing component107 and housing portion 104 are bonded and integrated together to forman airtight passage for clean air being emitted from the air cleaner.The bond in particular is formed between complementary edges 171 of themating channel 127 and half-duct channel 126 (only the edge of themating channel is shown in FIG. 3 a), each of which in the presentembodiment is an elongated rectangle that is rounded at one end. In atleast some such embodiments, the bond is achieved by way of a weldingprocess, such as hot plate welding, sonic welding, butt welding, etc. Inat least some other embodiments, the bond is achieved by way of a glueor adhesive. In still other embodiments, the bond is achieved by way ofbolts, screws or other fasteners, or by a combination of such fastenerswith glue or welding. Additionally, in alternate embodiments, thehousing portion 104 and additional housing component 107 are formedintegrally with one another; that is, the additional housing componentis formed as part of the housing portion 104.

FIG. 3 b shows a top view of the housing portion 104, that is, with therain cover 128 and end cap 105 both removed from the housing portion. Asshown, the housing portion 104 includes an inlet 90 into whichunfiltered air is drawn. Upon entering the inlet 90, the unfiltered airis directed within the housing portion 104 both axially andcircumferentially (e.g., helically) away from a front end 91 toward arear end 92 of the housing portion, where the circumferential motioninvolves movement along an exterior wall 144 of the housing portion,between the exterior wall and the filter element 108, so as to swirlaround the filter element 108. Arrows 51 and 52 show exemplarydirections of air flow as it enters the inlet 90 (arrow 51) and as theair continues to swirl around within the housing portion (arrow 52).

Also shown in FIG. 3 b is a substantially flat grate or grid 132extending from, and integrally formed with, the front end 91 of thehousing portion 104. As discussed further with reference to FIGS. 4 a-b,the grid 132 is surrounded by the rain cover 128 when the cover ispositioned onto the housing portion 104. Thus, substantially all of theair circulating within the rain cover 128 passes through the grid 132prior to entering the inlet 90 (except for possibly some minor excessflow between gaps formed between the perimeter of the grid and theinterior surface of the rain cover). Consequently, as a result of thegrid 132, particularly large debris never reaches the inlet 90 or entersthe housing portion 104. Additionally, as mentioned above and discussedfurther with respect to FIGS. 5-6, as a result the swirling motion ofthe unfiltered air within the air cleaner 100, dirt and other largedebris that enters the inlet 90 also tends to be removed from theswirling air due to centrifugal forces, before it enters and passesthrough the filter element 108.

Further, FIGS. 3 c and 3 d respectively show cross-sectional views ofthe housing portion 104 taken along lines C-C and D-D of FIG. 3 b,respectively. FIG. 3 c in particular shows a cross-sectional view of thehousing portion 104 taken vertically (or substantially vertically) alongan axial center line 199 of the housing portion 104, where the axialcenter line in the present embodiment is horizontal (or substantiallyhorizontal). Additionally, FIG. 3 c shows in phantom and partial cutawaythe filter element 108 as well as a secondary or redundant filterelement 118 positioned concentrically within the primary filter element108 as the filter elements would be positioned when the air cleaner 100was fully assembled (as shown, the filter elements extend out from thehousing portion 104 when positioned fully therein, and it is the end cap105 that in combination with the housing portion fully encloses thefilter elements within the air cleaner). Each of the filter elements108, 118 are supported by and sealed with respect to aninwardly-extending tubular extension 131 of the housing portion 104 thatleads to the outlet channel 117 of the housing portion. Also, each ofthe filter elements 108, 118 and the tubular extension 131 are axiallycentered about the axial center line 199.

As shown in FIG. 3 c, air entering the housing portion at the inlet 90generally follows a path indicated by a dashed line (and arrow heads)141. More particularly, upon entering the inlet 90, the air first swirlswithin an annular space 98 formed between the exterior wall 144 of thehousing portion 104 and a cylindrical intermediate inner wall 134extending within the housing portion, generally following a helicalpath. The air then continues to swirl within an annular chamber 142formed between the exterior wall 144 of the housing portion 104 and theprimary filter element 108, generally continuing to follow a helicalpath so as to move from the front end 91 toward the rear end 92 of thehousing portion 104. As a result, heavy dirt or dust particles movetoward the rear end 92 at which is located a one-way valve 137 (see FIG.3 a), by which this material is ejected out of the air cleaner 100, andwhich in at least some embodiments can be a metal or plastic reed valve,or a rubberized valve.

While the heavy dirt or dust particles helically flow toward the rearend 92, the unfiltered air does not indefinitely continue to flowhelically but rather eventually proceeds radially inward through theprimary filter element 108 and subsequently through the secondary filterelement 118, after which point the air (now filtered air) enters aninterior, axially-extending cylindrical cavity 146 within the secondaryfilter element. In at least some embodiments, the primary filter element108 is a pleated paper filter element, while the secondary filterelement 118 is a cloth or fibrous filter element. Upon reaching thecylindrical cavity 146, the air then proceeds out of the cavity throughthe tubular extension 131 and subsequently through the outlet channel117. The filtered air then further proceeds through a combinationpassage 148 formed by the half-duct channel 126 (e.g., the trough formedtherein) of the additional housing component 107 and the mating channel127 of the housing portion 104, and subsequently through and out theelbow 125, the output orifice of which is located to the side of thevertical cross-section shown in FIG. 3 c. FIG. 3 c further shows ajunction (or “weld line”) 95 between the additional housing component107 and the housing portion 104, where those two pieces are bonded,fastened, or otherwise coupled or joined together.

In comparison with FIG. 3 c, FIG. 3 d, which is taken along a verticalcross-section to the side of the vertical cross-section of FIG. 3 c,does not substantially show the tubular extension 131, the outletchannel 117, the combination passage 148, the half-duct channel 126, themating channel 127, the additional housing component 107, or the elbow125, since these elements are generally located proximate to thevertical cross-sectional plane of FIG. 3 c. FIG. 3 d also illustrates byway of an arrow 149 that the inlet 90 by which air flows into thehousing portion 104 extends over a fairly large circumferentialdistance.

Compared to the conventional system shown in FIG. 1, due to the use ofthe additional housing component 107 and housing portion 104 rather thanthe air duct 11, adapter 13, clamps 10, etc. of FIG. 1, the improved aircleaner 100 employs fewer parts and eliminates hose joints where airleakage can occur. As a result, the improved air cleaner 100 is lesslikely to have dirt or dust leaks into the clean combustion air incomparison with conventional designs such as that of FIG. 1.

Turning to FIGS. 4 a-b, the improved air cleaner 100 replaces the raincap 1 and associated upwardly-extending inlet of the housing 4 of FIG. 1with the low profile rain cover or hood 128 and the inlet 90 of thehousing portion 104. FIG. 4 a in particular shows the rain cover 128when removed from the housing portion 104. As shown, the rain cover 128is effectively an empty cup-shaped structure that has substantially thesame cylindrical diameter as both the housing portion 104 and the endcap 105, and is similar in its exterior shape to the end cap, butdiffers from the end cap particularly in that it includes an air inletopening 129 at or proximate its bottom. In the present embodiment, theopening 129 is effectively an aperture created by the absence of aportion of the cylindrical wall of the rain cover 128, and extends theentire axial length of the rain cover. Also in the present embodiment,the opening 129 has a first region 151 that is relatively narrow incircumferential extent at an open end 153 of the rain cover 128 thatfaces the housing portion 104 when assembled thereto, and also has asecond region 155 that is wider in circumferential extent farther awayfrom the open end 153.

In addition to the retaining clips/clasps 103 that couple the rain cover128 to the housing portion 104, a number of ribs 75 are formed along theexterior surface of the housing portion 104. When the rain cover 128 isassembled to the housing portion 104, an outer edge or lip 181 of therain cover overhangs or surrounds one or more of the ribs 75, such thata seal is formed between the rain cover and the housing portion. Amongother things, this seal serves to direct moisture away from the airinlet opening 129. In at least some embodiments, the ribs 75 extend bothcircumferentially around the housing portion 104 and axially along thesurface of the housing portion such that the seal formed by the ribs atthe interface of the rain cover and the housing portion is alabyrinth-type seal. In other embodiments, the ribs 75 only extendcircumferentially or axially, but not both, or extend in some otherarrangement. Although in the present embodiment the ribs 75 are formedon the housing portion 104, in alternate embodiments the ribs could beformed on the rain cover and/or on both the cover and the housingportion.

As mentioned above, the grid 132 is molded integrally with the housing104, and serves to prevent large dirt particles, debris, birds, rodents,etc. from entering the air cleaner 100. In the present embodiment asshown in FIG. 4 b, the grid 132 is a planar wall that extendshorizontally (e.g., relative to the vertical cross-section shown in FIG.3 c) along the axial center line 199. The grid 132 extends substantiallythe entire inner diameter of the rain cover 128 and also extends axiallyoutward sufficiently far so as to reach an inner end surface 157 of therain cover (see FIG. 4 a) when the rain cover is fully assembled to thehousing portion 104. In the present embodiment, the inner end surface157 of the rain cover 128 is further molded to include a slot 159 thatis configured to receive the far end of the grid 132 when the rain cover128 is fully coupled to the housing portion 104. In at least somealternate embodiments, a damping element (e.g., a round piece of closedcell foam material or rubber/elastomeric material) can also be providedwithin the rain cover 128, for example, within the slot 159, in order todamp vibrations.

When the rain cover 128 is fully assembled to the housing portion 104,the rain cover 128 interfaces both the grid 132 and the ribs 75 in sucha manner that substantially the only (or at least the primary) flowpassage from outside of the air cleaner 100 to the inlet 90 of thehousing portion is by way of the grid 132. Further, because the airinlet opening 129 is downwardly facing, air and other items entering theair cleaner 100 must enter from underneath the air cleaner (or at leastunderneath the rain cover 128). Consequently, due to the assembly of therain cover 128 to the housing portion 104, including the grid 132,rainwater (and other materials) are less likely to enter (or areentirely prevented from entering) the air cleaner 100, or at least thehousing portion. Further, because the rain cover 128 has the same orsubstantially similar dimensions as the housing portion, particularly interms of diameter and thus height (and in particular protrudessubstantially no higher than the top of the remainder of the aircleaner), the rain cover is much less obtrusive, and consequently theair cleaner 100 is easier to install and maintain, and is lesssusceptible to damage, than conventional air cleaners.

As discussed above, heavy duty air cleaners such as the present improvedair cleaner 100 employ centrifugal forces to fling the heavy dirtparticles and other small debris out of the induction air to pre-cleanthe air prior to entry into the filter elements 108, 118. FIGS. 5 and 6show additional cross-sections of the housing portion 104 shown in FIG.3 b, particularly in order to provide additional views of the helicalpath of incoming air into and within the housing portion 104, as well asto further illustrate the flow of filtered air through the elbow 125,half-duct channel 126 and mating channel 127 discussed above. Moreparticularly, as shown in FIG. 5, incoming air follows a curved pathindicated by an arrow 133. Prior to entering the inlet 90 of the housingportion 104, the air follows the curved path in part due to itsinteraction with the inner surface of the rain cover 128 (not shown).Upon entering the inlet 90, the air continues to follow the curved patharound the space 98 between the outer wall 144 of the housing portion104 and an intermediate inner wall 134 within the housing portion.

As should be evident from FIGS. 3 c-d, which also show the intermediateinner wall 134, the intermediate inner wall does not extend the entirelength of the housing portion 104 between the front and rear ends 91,92, but rather only extends a portion of that length. Thus, as discussedabove, after the air proceeds nearly all of the way around the housingportion 104 (e.g., nearly 360 degrees), it proceeds into the annularchamber 142 formed between the exterior wall 144 of the housing portion104 and the primary filter element 108, and then subsequently into thefilter element 108. It should be noted that, although FIG. 5 shows theinlet 90 to be along the left side, in fact that left side correspondsto the top of the air cleaner 100/housing portion 104.

As noted above, the shape of the housing portion 104 also imparts anaxial component to the air flow along the length of the housing. Inparticular, a shaped wall 135 shown particularly in FIG. 3 b (and alsoin FIGS. 3 c, 4 b and 7) imparts an axial component to the flow. Theshaped wall 135, which extends in a ramped, helical or screw-type mannerfor about 90 degrees around the circumference of the housing portion104, serves to direct the unfiltered air in a helical manner both due tothe passage of the air within the rain cover 128 along the exteriorsurface of the shaped wall prior to its entry into the inlet 90 (e.g.,due to the fact that the inlet 90 is generally located farther from thefront end 91 than the opening 129 of the rain cover), and also due tothe passage of the air within the housing portion 104 after passingthrough the inlet 90, particularly as it again circles around within thespace 98 so as to pass by the interior surface of the shaped wall. Dueto the shaped wall 135, air is caused to swirl or spiral toward the rearend 92 of the housing portion 104. Dirt and dust can then collect at theend of the housing opposite the air inlet 90, and be emitted via theone-way valve 137.

Because of the combination of the rain cover 128 and the housing portion104, and because the incoming unfiltered air is directed along both theinside surface of the shaped wall 135 as well as the exterior surface ofthe shaped wall, incoming air is directed in a helical, swirling motionover a greater distance within the improved air cleaner 100 than inconventional air cleaners. For example, in the conventional air cleaner3 shown in FIG. 1, incoming air is directed by way of the rain cap 1 andinput port 28 down a circular duct in the housing, and subsequently avane or wall with a somewhat helical shape imparts spin to the air overmerely about a quarter turn (e.g., about 90 degrees) inside the housing.In contrast, the improved air cleaner 100 is configured to positivelyexert force over 180 degrees upon the incoming unfiltered air so as toproduce helical (including axial) air flow, where the 180 degrees ofinfluence is distributed over about 450 degrees of overall air travel.

More particularly, since the shaped wall 135 extends approximately 90degrees and since both the interior and exterior helical surfacesprovided by the shaped wall produce helical (including axial) movementof the unfiltered air, the shaped wall positively causes helical airflow over about 180 degrees. That is, the shaped wall 135 impartshelical air flow both during the approximately quarter turn while theair is between the rain cover 128 and the housing portion 104 flowingalong the shaped wall, and also during the approximately quarter turnwhile the air is within the housing portion alongside the shaped wall.At the same time, the unfiltered air does not experience the interiorand exterior surfaces of the shaped wall 135 continuously, but rathermust travel about 270 degrees between the ending of the exterior surfaceand the beginning of the interior surface, such that the effect of thehelical surfaces is spread out over the course of about one full turnwithin the housing portion 104 and an additional quarter turn within therain cover 128 prior to entry into the inlet 90.

In short, in the improved air cleaner 100, the surfaces of the shapedwall 135 positively influence helical (including axial) flow over about180 degrees, and this 180 degrees of influence is spread out over 450degrees of flow path. In effect, the positive influence of the exteriorsurface of the shaped wall 135 is subsequently boosted by the additionalpositive influence of the interior surface of the shaped wall. As aresult, in comparison with conventional air cleaners such as that ofFIG. 1, the improved air cleaner 100 results in the creation of greaterhelical air motion, resulting in improved diversion of dirt and dust tothe one-way valve 137 and also resulting in less flow loss at the inlet90.

In some alternate embodiments, additional helical, ramped or othershaped surfaces like the shaped wall 135 can be provided at otherlocations as well to further enhance the helical motion of the airwithin the air cleaner 100. For example, with respect to FIG. 4 b, whilethe shaped wall 135 in the present embodiment is provided at a location79 on the housing portion 104, an additional similar ramped wall couldbe provided at a diametrically opposite location 77 along the housingportion 104. If the housing portion 104 is modified to include such anadditional shaped wall at the location 77, then the multiple shapedwalls of the air cleaner will positively influence air flow to producefurther helical movement of the unfiltered air over a greater distancethan 180 degrees, for example, over 210 degrees, 270 degrees, orpossibly even more (such a configuration is also provided in thealternate embodiment shown in FIG. 8 discussed below).

Referring still to FIGS. 5 and 6, additional cross-sectional views ofthe half-duct channel 126, mating channel 127 and elbow 125 are alsoprovided. More particularly, FIG. 5 shows the half-duct channel 126 tohave the trough-shape described above, and to be coupled to the matingchannel 127 along the junction 95 so as to form the combination passage148. FIG. 6 in turn shows where the combination passage 148 empties intothe interior orifice of the elbow 125 allowing for airflow out of theair cleaner 100 into another component such as a carburetor or intakemanifold, as indicated by an arrow 161. An optional orifice 163 is alsoshown in FIG. 6 to be formed within the half-duct channel 126. Theorifice 163 allows a pressure detection device such as a differentialpressure device or “filter minder” (not shown) to be coupled to the aircleaner 100, allowing for detection of when the air cleaner (andparticularly the filter elements 108, 118) are clogged or plugged (e.g.,with dirt) and need to be replaced. Otherwise, the orifice 163 typicallyis plugged with a plug when the air cleaner 100 is in use. It shouldfurther be noted that, although FIGS. 5 and 6 show the half-duct channel126, mating channel 127 and elbow 125 to be along the right sides of therespective figures, in fact those right sides correspond to the bottomof the air cleaner 100/housing portion 104.

Turning to FIG. 7, a more detailed, partially-exploded view is providedof the entire air cleaner 100 implemented in conjunction with a portionof an engine, namely, an exemplary carburetor assembly 88, which in thisexample includes both an intake manifold 139 and a carburetor 140. Inthis view, the end cap 105 and additional housing component 107 inparticular are still shown to be coupled to the housing portion 104 eventhough other components such as the rain cover 128 and the primary andsecondary filter elements 108, 118 are shown to be removed from thehousing portion. Nevertheless, it should be understood that both the endcap 105 and the rain cover 128 in the present embodiment are fastened tothe housing portion 104 by way of the retaining clips/attachment clasps103, albeit in other embodiments other fastening mechanisms could beemployed such as, for example, bayonet-type fastening mechanisms, twistand lock mechanisms, screws, bolts, snaps, etc. Also, while in FIGS. 3a, 4 a and 7, the attachment clasps 103 are shown to be primarilysupported by the housing portion 104 rather than the end cap 105 andrain cover 128, such that the clasps are only in contact with the endcap and rain cover when those components are assembled to the housingportion, in alternate embodiments, the clasps could instead be primarilysupported by the end cap and/or rain cover.

In the present embodiment, the air cleaner 100 also integrates themounting system into the housing design, as shown by way of FIG. 7 aswell as FIGS. 2 and 3 a. More particularly, features on the elbow 125such as bolt holes 165 match carburetor mounting fastener holes 86 onthe carburetor 140, such that bolts (not shown) can be used to fastenthe elbow directly to the carburetor. In the present example, thecarburetor 140 is a double-barreled carburetor, and so the orifice ofthe elbow 125 is oval-shaped (see FIGS. 2 and 3 a). However, inalternate embodiments employing a single-barreled carburetor the shapeof the orifice of the elbow could be modified (e.g., become circular).Additionally, holes and/or bosses 167 on the mounting brackets 138(again see FIGS. 2 and 3 a) are configured to mate to features 84designed into the intake manifold 139 so that the air cleaner 100 can bedirectly mounted upon the intake manifold.

In at least some other embodiments of the present invention, it isintended that the present invention encompass methods of assembling anair cleaner to a carburetor, intake manifold, other engine component, orother device by way of the above-described structures. Further, it isintended that the present invention in at least some embodimentsencompass methods of limiting the intake of water, animals, insects,and/or other debris into an air cleaner, and/or methods of impartinggreater amounts of helical motion upon unfiltered air entering the aircleaner, by way of the above-described structures (including directingair along both exterior and interior surfaces of a shaped wall). Also,it is intended that the present invention in at least some embodimentsencompass methods of operating an air cleaner that include the providingof a downwardly-opening rain cover in relation to the air cleaner anddirecting that air through the rain cover into the housing of the aircleaner.

Although FIGS. 2-7 and the related discussion above describe oneparticular embodiment of an improved air cleaner and several variationsthereof, the present invention is intended to encompass additionalembodiments of improved air cleaners as well. For example, referring toFIGS. 8-10, a further embodiment of an improved air cleaner is similarto the improved air cleaner 100 except insofar as it employs a slightlydifferent housing portion 200 and complementary additional housingcomponent 210. As shown particularly in FIG. 8, which provides aperspective view of the housing portion 200, the housing portion isidentical to the housing portion 104 except in a few respects. First,the housing portion 200 has a differently-configured mating channel 202having an edge 204 that is generally foot-shaped, where the widersection of the foot-shaped mating channel is at the end of the channelopposite the end that receives air from the outlet channel 117 of thehousing portion. Second, the housing portion 200 has multiple curved (inthis example, L-shaped) fins 206 extending from within the matingchannel 202 outward away from the housing portion. Third, the housingportion 200 has an additional shaped wall 205 located in the region ofthe housing portion corresponding to the region 77 described above withrespect to FIG. 4 b and thus, in this embodiment, the housing portion iscapable of imparting even greater force upon incoming air tending tocause helical air flow within the housing portion than is provided bythe air cleaner 100 described above.

As for the complementary additional housing component 210, as shown inFIG. 9, that component is similar to the additional housing component107 in that it includes a half-duct channel 214 forming a trough and anelbow 218 leading outward from the trough to an outlet orifice 226.However, in contrast to the housing component 107, an edge 212configured to mate with the edge 204 of the mating channel 202 is alsogenerally foot-shaped like the mating channel (as is the half-ductchannel 214 itself). Also, the half-duct channel 214 of the additionalhousing component 210 is formed to include a tongue-like extension 216that rounds the inner bottom surface of the housing component at the endof the housing component opposite the end at which is located the elbow218. In the present embodiment, the tongue-like extension 216 extendssomewhat above and past the edge 212 of the half-duct channel 214.Further, in addition to including a first orifice 220 corresponding tothe orifice 163 of FIG. 6, which can be coupled to a filter minder, theadditional housing component 210 also includes a second orifice 222proximate the tongue-like extension 216 by which a carburetor vent linecan optionally be coupled to the half-duct channel 214, as well as athird orifice 224 proximate the first orifice by which a breather hosecan be optionally coupled to the half-duct channel (again, each of theorifices 220-224 is optional and can alternatively be plugged ratherthan coupled to any of the above-mentioned structures).

FIG. 10 additionally provides a cross-sectional view showing an assembly230 of the additional housing component 210 and the housing portion 200when assembled along a weld line 228, taken along a line 10-10 of FIG. 8(as the cross-section would appear if the two components were shown tobe assembled in FIG. 8). As shown, when assembled, the tongue-likeextension 216 protrudes somewhat into the outlet channel 117 of thehousing portion 200, while the fins 206 protrude into the trough formedby the half-duct channel 214 (and even possibly slightly into the elbow218). It should be understood that, while the present embodimentincludes both the fins 206 and the tongue-like extension 216, inalternate embodiments only one or the other of these features can bepresent. Further, it should also be recognized that a similar additionalhousing component having a tongue-like extension could be used incombination with the housing portion 103 of FIGS. 2-7.

In the embodiment of FIGS. 8-10 or similar embodiments employing finssuch as the fins 206, the fins can serve to enhance or otherwise modifythe quality (and/or quantity) of airflow out of the elbow (not shown)into a carburetor/intake manifold. For example, the fins 206 can limitturbulence of the air flow, compensate for excessive air flow proximateone or another of the walls of the combination passage/elbow, or affectjets of the carburetor. Also, in embodiments employing the tongue-likeextension 216, the tongue-like extension can further serve to enhanceair flow from the outlet channel of the housing portion into the passageformed by the half-duct channel and mating channel, for example, byreducing stalling of air flow.

Although the fins 206 and tongue-like extension 216 are shown in FIGS.8-10, one or more protrusions having shapes other than those of the finsor tongue-like extension can also be employed depending upon theembodiment. Also, in some embodiments, fins or other protrusions couldbe formed within the additional housing component rather than within themating channel of the housing portion, or within both the additionalhousing component and the housing portion. Likewise, in someembodiments, a tongue-like extension could be formed as part of thehousing portion rather than as part of the additional housing component.Further, in some embodiments, one or more pieces separate from thehousing portion and the additional housing component can be inserted inbetween those structures (e.g., between the edges of those structures orwithin the combination passage formed by those structures) to influenceair flow.

Many additional embodiments of air cleaners having one or more featuresdiffering from those described above are also intended to be encompassedby the present invention. For example, while the channel 126 is abovereferred to as a “half-duct channel”, the above figures make it clearthat actually the trough formed within that channel encompasses morethan half of the combination passage 148 formed by that channel and themating channel 127. It should be understood that, depending upon theembodiment, such channels can be configured in various additional waysto form a variety of combination passages that are formed to varyingdegrees by the respective channels. Also for example, while the elbow125 described above has an outlet orifice that empties toward the sideof the air cleaner 100, in alternate embodiments the elbow could bemodified so that it directed flow in various other directions (e.g.,straight downward). Further for example, the L-shaped fins describedabove need not be L-shaped in other embodiments and instead could bemerely flat fins.

Additionally, while the above description often refers to particularorientations of air cleaners such as the air cleaner 100 and variouscomponents thereof, it should be understood that these describedorientations are only exemplary and need not be maintained in everyembodiment. For example, while the axial center line 199 is describedabove as being horizontal (or substantially horizontal), in alternateembodiments, the axial center line 199 could be oriented vertically (orsubstantially vertically). In such embodiments, the orientation of theair inlet opening 129 could be modified from that shown. For example,the rain cover could be oriented at the bottom of the air cleaner andhave an air inlet opening that was along the end of the rain coverrather than along its side, so as to be downwardly-facing.

It is specifically intended that the present invention not be limited tothe embodiments and illustrations contained herein, but include modifiedforms of those embodiments including portions of the embodiments andcombinations of elements of different embodiments as come within thescope of the following claims.

We claim:
 1. An air cleaner comprising: a filter element; a housingwithin which is positioned the filter element and further having aninlet and an outlet, the outlet being formed by way of an integratedextension, wherein the integrated extension is configured to allow thehousing to be directly coupled to at least one of a carburetor and anintake manifold without any intermediate air duct.
 2. The air cleaner ofclaim 1, wherein the housing includes a primary housing portion and anadditional housing component that is coupled to the primary housingportion, and wherein the integrated extension is formed from one or bothof the primary housing portion and the additional housing component. 3.The air cleaner of claim 2, wherein the additional housing component iscoupled to the primary housing portion by way of welding, glue or afastening device, and wherein the integrated extension is configured toallow the housing to be directly coupled to the carburetor or intakemanifold without any intermediate hose.
 4. The air cleaner of claim 2,wherein the additional housing component includes a half-duct channeland an elbow, wherein the primary housing portion includes an outletchannel and a mating channel, and wherein coupling of the additionalhousing component and the primary housing portion results in acombination passage by which the outlet channel is coupled to the elbow.5. The air cleaner of claim 2, wherein at least one protrusion extendswithin the outlet, the protrusion serving to influence a flow pattern ofthe air flowing within or out of the outlet.
 6. The air cleaner of claim5, wherein the at least one protrusion includes at least one fin.
 7. Theair cleaner of claim 6, wherein the at least one protrusion includes aplurality of L-shaped fins that protrude from a bottom surface of theprimary housing portion.
 8. The air cleaner of claim 5, wherein the atleast one protrusion includes a tongue-like extension.
 9. The aircleaner of claim 8, wherein the tongue-like extension extends from aninner portion of the additional housing component into the primaryhousing portion.
 10. The air cleaner of claim 2, wherein the additionalhousing component includes at least one orifice, and wherein at leastone of a breather hose, a carburetor vent line, and a pressure sensingdevice is capable of being coupled to the at least one orifice.
 11. Theair cleaner of claim 1, wherein at least one of the following is true: asubstantial portion of the housing is manufactured from molded plastic;and the integrated extension is integrally formed as part of thehousing.
 12. The air cleaner of claim 1, further comprising at least oneof an end cap and a rain cover.
 13. The air cleaner of claim 12, whereinthe air cleaner includes the rain cover, wherein the rain cover has anopening proximate a bottom surface of the rain cover to allow entry ofunfiltered air, and wherein a preponderance of the rain cover does notextend substantially higher than the housing.
 14. An engine assemblyincluding the air cleaner of claim
 1. 15. An air cleaner comprising: afilter element configured to filter air; a housing portion within whichis positioned the filter element, wherein the housing portion includes ashaped wall, wherein the shaped wall includes an exterior surface and aninterior surface, and wherein the shaped wall influences a path of theair that is to be filtered both as the air passes alongside the exteriorsurface and as the air passes alongside the interior surface.
 16. Theair cleaner of claim 15, further comprising a rain cover that ispositioned so as to at least partly enclose the shaped wall, wherein thepath of the air is influenced by the exterior surface of the shaped walldue at least in part to a presence of the rain cover.
 17. The aircleaner of claim 15, wherein the shaped wall imparts a helical air flowpath to the air.
 18. The air cleaner of claim 15, further comprisingintegrated means for coupling an outlet of the housing portion to atleast one of a carburetor and an intake manifold.
 19. The air cleaner ofclaim 15, further comprising at least one bracket integrally formed uponthe housing portion, by which the air cleaner can be directly coupled toan engine assembly, and wherein the air cleaner is a heavy duty aircleaner.
 20. A method of operating an air cleaner, the methodcomprising: receiving air at a downwardly-opening orifice formed withina rain cover; imparting a helical motion upon the air as it proceedswithin a first chamber formed between the rain cover and a housingportion; providing the air into an inlet of the housing portion; furtherimparting the helical motion upon the air as it proceeds within a secondchamber of the housing portion; filtering the air; and outputting thefiltered air.
 21. The method of claim 20, wherein the outputted filteredair is output directly to at least one of a carburetor and an intakemanifold by way of an extension integrated with the housing portion.